Protesters in Chicago rally against President Trump’s decision to exit the Paris climate accord. With the federal government stepping back from the global agreement to curb greenhouse-gas emissions, a coalition that includes more than 100 college presidents intends to take up the mantle.

At most of the nearly 120 colleges and universities whose presidents had signed a pledge Friday to meet the goals laid out in the Paris Climate Agreement, the signatures won’t lead to a sea change. These are institutions, by and large, that have already committed to reduce their carbon footprint.

But in joining a coalition of business leaders, mayors, and governors set on helping the United States meet international targets for greenhouse-gas emissions, the institutions are attempting to send a clear message: Now that President Trump has pulled the United States out of the climate accord, we’ll fill a leadership void on a global issue.

The coalition, coordinated by the former New York City mayor Michael Bloomberg, is negotiating with the United Nations on how to enter the Paris agreement and report on its progress, according to The New York Times. College presidents joined the mayors of Los Angeles, Atlanta, Salt Lake City, and Pittsburgh; the governors of California, Massachusetts, New York, and Washington, who are creating a separate alliance of states; and the heads of Hewlett-Packard, Mars Inc., and other companies in committing to meet the guidelines for greenhouse-gas emissions outlined in the Paris accord.

As producers of research and early adopters of sustainable-energy sources, colleges and universities have long been on the frontlines of efforts to combat climate change. But the new coalition is part of a broader effort by the institutions to bring "the totality of their assets to bear," said Robert C. Orr, dean of the University of Maryland’s School of Public Policy. As the United Nations’ special adviser to the secretary-general on climate change, Mr. Orr helped draft the Paris accord, which was signed by representatives of nearly 200 nations in 2015.

Over the years, Mr. Orr said, universities have become more sophisticated in how they contribute to the global campaign against climate change. University research has moved beyond the science of global warming to assess factors like the impact of climate change on the economy. Debates about divesting from the coal industry have transformed into discussions about how university endowments can support an emerging clean-energy sector. And the work campuses have done to make themselves greener is now being replicated by big businesses that have campuses of their own.

"A lot of universities have been walking the walk," Mr. Orr said. "Many universities, like my own, are small cities. The idea that academic institutions have to live their values on something as fundamental as sustainability has led to major investments in sustainable practices."

‘We Are Still In’

"To my knowledge we haven’t seen a shared statement of such strong alignment at the senior level," said Timothy Carter, president of Second Nature, a nonprofit that works with colleges and universities on climate-change efforts. The group, which is coordinating with higher-education officials who wish to join the accord, has posted a page on its website where presidents can add their names to the statement before June 5.

The presidents of Brandeis, George Washington, Northeastern, Portland State, and Wesleyan Universities, Agnes Scott and Emory and Henry Colleges, the University of California at Merced, California State University at Northridge, and Lamar Community College, are among the signatories, according to Mr. Carter.

Some university presidents who signed said they did not see their signatures as a political statement but as an affirmation of the basic responsibilities of higher-education institutions. From a practical standpoint, they said, the statement will not change their emissions policies because they are already making efforts to reduce their carbon output.

"I think it’s quite extraordinary that supporting a basic commitment to lessen a source of pollution in the world is seen as a particularly strong civic or political act," said Michael S. Roth, president of Wesleyan. "At a time when the White House is promoting an anti-scientific assault on public policy and research, it’s really important for universities and especially university leadership to defend the values that are necessary for us to be institutions of learning."

Mr. Roth said his university had already divested from coal and made efforts to make its campus more energy-efficient. In May, Wesleyan drafted a building-sustainability policy that establishes how the campus will choose building materials and use energy and water in ways that reduce its carbon footprint.

Brandeis, meanwhile, is pursuing building-management strategies to reduce its carbon emissions. "The university stands for the pursuit of knowledge and scientific inquiry," said Ronald D. Liebowitz, the president. "I see it as a responsibility. We recognize the science."

‘They’re at the Table’

Even if the statement amounts to a certification of work already being done, signing it carries real weight, some university officials said. In their eyes, it puts institutions in a position to act as community leaders, taking up an issue on which the federal government has chosen to punt.

"The incentives to deliver on your promises go up when public promises have been made," Mr. Orr said. "Universities have not been at the center of the universe when the nonstate actors engage in the climate efforts. They get overshadowed by big business."

"Participating in things like this do bring the network of universities closer into the coordination of the efforts to advance climate action," he added. "They’re at the table, to use the phrase of the day, even if the United States government is not."

"It is imperative that the world know that in the U.S., the actors that will provide the leadership necessary to meet our Paris commitment are found in city halls, state capitals, colleges and universities, investors and businesses," reads the statement. The pledge’s power lies largely in the cooperation between the higher-education sector and the leaders of businesses and local-government agencies with institutions of higher education, said Steven Knapp, president of George Washington.

"Partnerships between businesses and institutions and governments can actually make a difference in combating climate change," Mr. Knapp said.

Linda Lujan, president of Lamar Community College, in Lamar, Colo., agreed. "Not only colleges and universities but K-12 institutions, businesses and industry, local and state governments are saying: ‘We can do this. We can continue to take action,’" she said. "To see so many diverse leaders from all the industry sectors stepping up and saying, ‘We will continue to commit’ — that is a powerful statement."

Mr. Knapp said he believes the federal government’s skeptical stance toward climate change and sustainability will have a whiplash effect. In recent years, some advocates have wondered whether the drive for more sustainable campuses had stalled. Now those who are passionate about preservation and clean energy, he said, are galvanized by the federal government’s inaction. He argued that local governments — including those that have signed the climate pledge — will fill the vacuum.

That’s not simply a matter of altruism, Mr. Orr said. Like businesses recognizing that their customers care how sustainably their products are made, universities must curb their carbon emissions to attract the best students and faculty.

"I was drawn to a university that was good on these issues," he said, noting that the University of Maryland at College Park has also signed the statement. "These things matter to the kinds of people I’m trying to recruit."

Months in the Making

Though the presidents’ pledge came quickly on the heels of President Trump’s decision to abandon the Paris accord, its foundation had been laid much earlier.

Second Nature, the group organizing college presidents’ support, was established in 1993 to encourage colleges to embrace sustainable practices. The organization has helped form networks of colleges and universities that collaborate in these efforts, including the Education for Sustainability Western Network. In 2006 it helped assemble 12 college presidents to draft the American College & University Presidents’ Climate Commitment, a compact through which institutions pledged to measure greenhouse-gas emissions and develop a plan to achieve "climate neutrality." By the following year, more than 300 institutions had signed the commitment. (Mr. Knapp, who joined George Washington in 2007, signed in his first year as president.)

Second Nature has been preparing for President Trump to quit the climate accord for a while, said Ms. Lujan, who is a member of the steering committee of the organization’s Climate Leadership Network. Planning for the pledge began months ago, she said, when Mr. Trump, then just a candidate for office, decried the Paris accords.

Even when he continued to critique the accords as president-elect, some members of the group held out hope that Mr. Trump would not pull the United States out, Ms. Lujan said. But the group began reaching out to the several hundred college and university leaders who, like Mr. Knapp, had previously signed climate commitments. The group also began reaching out to local governments and businesses to join the pledge.

Wim Wiewel, the departing president of Portland State University, said the pledge went through several drafts before the committee settled on the final version — a reflection of the "incredibly broad coalition" of interests involved.

The emissions goals laid out in the Paris accord offer a concrete way for colleges that sign the pledge to hold themselves accountable, said Mr. Carter, of Second Nature. Beyond that, he said, the goal "is obviously engaging the community, which is a little less specific to any one metric that everyone would agree upon. Outside of carbon, it’s going to be a more nuanced answer to measuring success."

American higher education has a responsibility to lead communities on issues of importance, Mr. Wiewel said, and it also has a responsibility to students who will live in a world affected by climate change.

Mr. Wiewel said it is the responsibility of educators to instill a greater understanding of — and respect for — the environment.

"This is not about indoctrinating people or preaching a new gospel," he said. "It’s about making people aware of our relationship to the air and the water around us."